<div class="main">
    <input type="checkbox" id="chk" aria-hidden="true">

    <div class="login">
        <form class="form">
            <label for="chk" aria-hidden="true">Log in</label>
            <input class="input" type="email" name="email" placeholder="Email" required="">
            <input class="input" type="password" name="pswd" placeholder="Password" required="">
            <button>Log in</button>
        </form>
    </div>

    <div class="register">
        <form class="form">
            <label for="chk" aria-hidden="true">Register</label>
            <input class="input" type="text" name="txt" placeholder="Username" required="">
            <input class="input" type="email" name="email" placeholder="Email" required="">
            <input class="input" type="password" name="pswd" placeholder="Password" required="">
            <button>Register</button>
        </form>
    </div>
</div>